Its a 20 gallon tank with 2 ryukin I bought over a year ago. One is perfectly healthy and growing. They were the same size when I got them. The healthy one has a body length of about 1.5-2", the sick one is only 1".
I used to have some plants in the tank but removed them a month ago because i thought they might be lacking space which was stunting their growth. Now there's just gravel and two logs.
I alternate between goldfish crisps and freeze-dried bloodworms. I read that they have too much protein so I try to give them peas once a week. I find it inconvenient to deshell the peas so don't give them as much veggies as i should.
When I got them, the fish store told me to feed once a day. When i come near the tank in the morning/afternoon, they swim around looking for food. I've always resisted a second feeding for fear of overfeeding them.
Ammonia/No2/No3 are 0. Ph is 7.2-7.6 (the chart doesn't have anything in between). Based on the blueish colour, its probably 7.4-7.5.
Temp is about 78. It fluctuates a few degrees, despite the fact that I have a heater. I had it replaced several months ago thinking it was defective but this one does the same thing. I recently read that it should be placed near the filter. I had it at the other end and just moved it, so will see if that makes it more stable.
I tried feeding peas exclusively for 2 weeks a few months ago, hoping to permanently get rid of the constipation, but it came back.
I'll pick up some pellets and continue with the peas to see if that helps.
He looks a little better today. I started him back on the peas yesterday. I see a bit of brown poop coming out. He's never had the really long strings of poop the other one has, but its an improvement.
In the past, the constipation caused him to float upside down. Sitting at the bottom of the tank is new behaviour.